Actuator assembly

ABSTRACT

An actuator assembly ( 10 ) including a motor ( 1 ) having a body portion ( 14 ) and a drive shaft ( 16 ), the drive shaft being drivably connected to a pinion ( 18 ), the pinion drivingly engaging an array of gear teeth ( 20 ) of a gear rack ( 22 ) the array of gear teeth having a first side ( 21 ) adjacent the motor, in which the gear rack is pivotally mounted via a pivot about a pivot axis ( 25 A) on said first side ( 21 ) of the array of gear teeth ( 20 ).

BACKGROUND OF THE INVENTION

The present invention relates to actuator assemblies and in particularelectrical actuators used to actuate components, for example door locks,door latches or door deadlocks in vehicles.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compact actuatorassembly. It is a further object to provide an actuator assembly that iseasy to install. It is a further object to provide an actuator assemblythat has relatively few components and is relatively cheap to produce.

Thus according to the present invention there is provided an actuatorassembly including a motor having a body portion and a drive shaft, thedrive shaft being drivably connected to a pinion, the pinion drivinglyengaging an array of gear teeth of a gear rack the array of gear teethhaving a first side adjacent the motor, in which the gear rack ispivotally mounted via a pivot about a pivot axis on said first side ofthe array of gear teeth.

Preferably the pivot axis passes through the body and/or is proximatethat end of the motor remote from the pinion.

Preferably the gear rack includes at least one stop to limit movement ofthe rack relative to the body portion and preferably the drive shaftpasses between the array of gear teeth and a guide portion proximate thegear teeth.

Preferably each stop supports the guide portion.

According to a further aspect of the invention there is provided anactuator assembly including a motor having a body portion and a driveshaft, the drive shaft being drivably connected to a pinion, the piniondrivingly engaging an assay of gear teeth of a gear rack with the gearrack being mounted for movement on the body portion.

Preferably the motor is an electric motor.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only withreference to the drawings in which; —

FIG. 1 is an isometric view of a top side of the present invention;

FIG. 1A is a schematic view of a top portion of a housing;

FIG. 1B is a schematic view of a bottom portion of the housing;

FIG. 1C is a partial cross-sectional view of the housing supporting adrive shaft of the motor

FIG. 2 is a isometric view of a back side of the present invention; and

FIG. 3 is an isometric view of a bottom side of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1–3 there is shown an actuator assembly 10 whichincludes a motor 12 (in this case an electric motor). The motor includesa body portion 14 and a drive shaft 16. The drive shaft is drivablyconnected to a pinion 18. The pinion 18 drivingly engages an array ofgear teeth 20 fixed to a gear rack 22.

The gear rack is of generally octant shape with the array of gear teeth20 being arranged in an arcuate manner. The array of gear teeth have afirst side 21 adjacent the motor. The gear rack includes a boss 24 whichfits into a hole 40 of a housing 42 to provide a pivot. Gear rack 22thus can rotate about axis 25A of boss 24. It should be noted the axis25A passes through body portion 14.

The housing 42 substantially surrounds the motor and gear rack and canbe substantially sealed against the ingress of contaminants eg. dirt,dust, or water. The motor is secured in the housing 42, preferably byengagement of each end of the drive shaft with the housing 42.

Preferably the housing 42 is of at least two part form, a first part 44having two cut-outs 46 (only one of which is shown), each cut-out 46accepting and supporting one end of the drive shaft, a second part 48having complementary cut-outs 50 (only one of which is shown) which inconjunction with the cut-outs of the first part 44 provide a journalbearing for each end of the drive shaft 16. The second part 48 also hasa hole 40 to accept and provide a journal for boss 24.

In use the boss 24 is connected to a lever 52 situated on the outside ofthe housing 42. The lever 52 being connected to the component to beactuated.

Extending beyond the gear teeth 20 there are two stops 26 and 28 whichlimit movement of the gear rack relative to the body portion 14 byengagement with the drive shaft 16. FIG. 1 shows the gear rack 22 at anextreme position wherein stop 28 has engaged drive shaft 16. FIG. 1 alsoshows (in chain dotted line) the other extreme of movement of the gearrack relative to the body portion wherein stop 26 has engaged driveshaft 16.

Guide portion 30 connects stops 26 and 28, resulting in a strongerarrangement. Guide portion 30 is mounted on the opposite side of shaft16 to the array of gear teeth 20. Guide portion 30 includes a guidesurface 32 along which the drive shaft 16 passes in close proximity oralternatively in light engagement therewith. When the motor 12 isproducing torque the engagement of the pinion with appropriate gearteeth of the array causes a separating force which preferably can becounteracted by the guide surface 32 acting upon the drive shaft 16,thus reducing the load as seen by the pivot 25.

In use operation of the motor in a first rotational direction causes thepinion to move the gear rack to a first position and operation of themotor in a second rotational direction causes the pinion to move thegear rack to a second position.

In further embodiments the gear rack can be of an alternative segmentshape such as a quadrant or a sextant and in yet further embodiments thegear rack need not be of a segment shape.

The invention provides for a particularly compact arrangement since asubstantial part of the gear rack can be arranged to lie alongside themotor. Furthermore the actuator assembly is axially compact, it beingnoted that no part of the gear rack projects beyond that end of thedrive shaft having the pinion secured thereto. It should also be notedthat the actuator shown in the figures only has two moving parts namelythe drive shaft/pinion and the gear rack.

The foregoing description is only exemplary of the principles of theinvention. Many modifications and variations of the present inventionare possible in light of the above teachings. The preferred embodimentsof this invention have been disclosed, however, so that one of ordinaryskill in the art would recognize that certain modifications would comewithin the scope of this invention. It is, therefore, to be understoodthat within the scope of the appended claims, the invention may bepracticed otherwise than as specially described. For that reason thefollowing claims should be studied to determine the true scope andcontent of this invention.

1. An actuator assembly including a motor having a body portion, a driveshaft, and a pinion directly fixed to the drive shaft to always rotatein unison with the drive shaft, the pinion drivingly engaging an arrayof gear teeth of a gear rack, the array of gear teeth having a firstside adjacent the motor, and the gear rack is pivotally mounted via apivot for movement about a pivot axis wherein said pivot axis is on amotor side of said array of gear teeth.
 2. The actuator assembly asrecited in claim 1 in which the pivot axis passes through the bodyportion.
 3. The actuator assembly as recited in claim 1 in which thepivot axis is proximate an end of the motor remote from the pinion. 4.The actuator assembly as recited in claim 1 in which the gear rackincludes at least one stop to limit movement of the rack relative to thebody portion.
 5. The actuator assembly as recited in claim 4 in whicheach stop engages the drive shaft.
 6. The actuator assembly as recitedin claim 5 in which each stop engages a portion of the drive shaft onthe side of the pinion remote from the motor.
 7. The actuator assemblyas recited in claim 4 in which the drive shaft passes between the arrayof gear teeth and a guide portion proximate the gear teeth.
 8. Theactuator assembly as recited in claim 7 in which the guide portion issupported by each stop.
 9. The actuator assembly as recited in claim 1which further includes a housing in which the motor is secured.
 10. Theactuator assembly as recited in claim 9 in which the pivot is mounted onthe housing.
 11. The actuator assembly as recited in claim 9 in whichthe pivot includes a boss of the gear rack to which in use a lever isattached.
 12. The actuator assembly as recited in claim 11 in which theboss at least partially projects through the housing.
 13. The actuatorassembly as recited in claim 9 in which the drive shaft engages thehousing.
 14. The actuator assembly as recited in claim 9 in which thehousing is substantially scaled.
 15. The actuator assembly as recited inclaim 9 in which the housing has at least a first and second part, theparts having cooperating cut-outs to provide for at least one end of thedrive shaft.
 16. The actuator assembly as recited in claim 1 in whichthe pivot is mounted on the body portion.
 17. An actuator assemblyincluding a motor having a body portion, a drive shaft, and a piniondirectly fixed to the drive shaft to always rotate in unison with thedrive shaft, the pinion drivingly engaging an array of gear teeth of agear rack with the gear rack mounted for movement on the body portion.18. The actuator assembly as recited in claim 17 in which the motor isan electric motor.
 19. An actuator assembly comprising a motor having abody portion and a drive shaft, the drive shaft being drivably connectedto a pinion, the pinion drivingly engaging an array of gear teeth of agear rack pivotally mounted for movement about a pivot axis, the arrayof gear teeth having a first side adjacent the motor and at least onestop engaging the drive shaft to limit movement of the gear rackrelative to the body portion.